1. Field of the Invention
This invention relates generally to the field of magnetic circuits for electronic devices, and more specifically to a magnetic circuit including a structure for magnetically cladding the circuit to eliminate undesirable exterior magnetic fields.
2. Description of Prior Art
Various magnetic devices requiring a controlled magnetic field, such as klystrons, traveling wave tubes, microwave devices, and other magnetic circuits, have employed magnetic cladding to help intensify the desired controlled magnetic field as well as to reduce the external effects of the magnetic circuit on the surrounding environment due to magnetic field leakage.
Those concerned with the development of magnetic cladding devices have long recognized the need for improving the magnetic intensity per unit weight of magnetic circuits, thereby improving the overall size and cost of such devices. For example, Neugebauer U.S. Pat. No. 3,768,054, entitled "Low Flux Leakage Magnetic Construction" discloses a number of magnetic circuits each having a magnetic cladding means mounted thereon. These various prior-art cladding devices produce cladded circuits that reduce the exterior flux leakage and increase the desired controlled magnetic field intensity without appreciably increasing the size or weight of the magnetic circuit. More specifically, in the Neugebauer patent, the magnetic flux of a first magnet is conserved by placing a second permanent magnet adjacent the first magnet with the magnetic axis of the second magnet perpendicular to the axis of the first magnet to prevent leakage of flux from the first magnet. As a result, most of the flux generated by the first magnet in directions skewed from the main axis is redirected to increase the magnetic intensity along the main axis. Although prior-art devices such as Neugebauer's have served the purpose, they have not gone far enough in maximizing size and weight reduction.